The Lipid Paradox is present in ST-elevation but not in non-ST-elevation myocardial infarction patients: Insights from the Singapore Myocardial Infarction Registry

Abstract

Lowering low-density lipoprotein (LDL-C) and triglyceride (TG) levels form the cornerstone approach of cardiovascular risk reduction, and a higher high-density lipoprotein (HDL-C) is thought to be protective. However, in acute myocardial infarction (AMI) patients, higher admission LDL-C and TG levels have been shown to be associated with better clinical outcomes-termed the 'lipid paradox'. We studied the relationship between lipid profile obtained within 72 hours of presentation, and all-cause mortality (during hospitalization, at 30-days and 12-months), and rehospitalization for heart failure and nonfatal AMI at 12-months in ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) patients treated by percutaneous coronary intervention (PCI). We included 11543 STEMI and 8470 NSTEMI patients who underwent PCI in the Singapore Myocardial Infarction Registry between 2008-2015. NSTEMI patients were older (60.3 years vs 57.7 years, p < 0.001) and more likely to be female (22.4% vs 15.0%, p < 0.001). In NSTEMI, a lower LDL-C was paradoxically associated with worse outcomes for death during hospitalization, within 30-days and within 12-months (all p < 0.001), but adjustment eliminated this paradox. In contrast, the paradox for LDL-C persisted for all primary outcomes after adjustment in STEMI. For NSTEMI patients, a lower HDL-C was associated with a higher risk of death during hospitalization but in STEMI patients a lower HDL-C was paradoxically associated with a lower risk of death during hospitalization. For this endpoint, the interaction term for HDL-C and type of MI was significant even after adjustment. An elevated TG level was not protective after adjustment. These observations may be due to differing characteristics and underlying pathophysiological mechanisms in NSTEMI and STEMI.

Risk factors for in-hospital death in acute ST-segment elevation myocardial infarction after emergency percutaneous coronary intervention: a multicenter retrospective study

“…In this study, high LDL-C was a protective factor, which is counterintuitive given the role of LDL-C levels in the development of AMI (4)(5)(6)(7). This LDL-C paradox has been reported in many studies (34)(35)(36)(37). Sia et al (34) reported that high LDL-C was protective in STEMI, while low HDL-C was protective in STEMI.…”

Prognostic implications of calculated Apo‐lipoprotein B in patients with ST‐segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: Outcome is tied to lower cut‐points

“…Albeit, these reports often did not differentiate between the subgroups with STEMI and Non‐STEMI. Conversely, a recent large study postulate that the paradoxical correlation of baseline lipid profile with MACE is limited to serum LDL‐C 31 …”

“…30 Albeit, these reports often did not differentiate between the subgroups with STEMI and Non-STEMI. Conversely, a recent large study postulate that the paradoxical correlation of baseline lipid profile with MACE is limited to serum LDL-C. 31 Increased TG-rich lipoproteins, low HDL-C and usually normal LDL-C levels characterize lipid profile of subjects with metabolic syndrome and insulin resistance. However, frequency of atherogenic particles including small dense LDL-C increases that tend to get oxidized.…”

Association between low-density lipoprotein cholesterol level and mortality in patients with cardiogenic shock: a retrospective cohort study

“…10 11 However, a number of studies have reported a protective association between higher concentrations of LDL-C and ACS. [13][14][15] In the Global Registry of Acute Coronary Events mortality model, lower in-hospital mortality was associated with hypercholesterolaemia in patients with ACS. 16 Meanwhile, an increased level of LDL-C was also associated with a lower risk of 30-day mortality, 1 year mortality and even 5-year mortality in patients with ACS, [13][14][15][16] respectively.…”

“…12 Recent studies have found that initial LDL-C level was inversely associated with mortality in patients with ACS. [13][14][15][16] Meanwhile, data from large observational studies revealed that LDL-C may function as an inflammatory biomarker and is predictive of poor outcome in those with rheumatoid arthritis, heart failure, stroke and atrial fibrillation. [17][18][19][20][21][22][23] Thus, we hypothesised that LDL-C may affect the prognosis of CS.…”